Regulating transformer



A. L. ATHERIUN.

REGULATING TRANSFORMER.

APPLICATION FILED JUNE 18, 1919.

Patented Nov. 14, 1922.

2 SHEETSSHRET I.

INVENTOR A/frea L. A/fierfafl ATTORNEY A. L. ATHERTON.

REGULATING TRANSFORMER.

APPLICATION FILED JUNE 18, I919.

1,435,195, Patented Nov. 14, 1922.

2 SHEETS-SHEET 2.

INVENTOR A/fredL. Af/ierfon ATTORNEY WITNESSES:

Patented Nov. 14, 1922.

UNITED'STATES PATENT OFFICE.

ALFRED L. AT-HERTON, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC G: MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA.

BEGULATING TRANSFORMER.

Application filed June 18, 1919. Serial No. 305,130.

To all to hem it may concern:

Be it known that I, ALFRED L. ATHERTON, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Regulating Transformer, of which the following is a specification.

My invention relates to transformers and it has particular relation to transformers which are adapted to regulate the current furnished thereby and which are commonly known as constant-current transformers.

In the accompanying drawing, Figure 1 is a top planview of a transformer embodying my invention; Fig. 2 is a side view of the same transformer, partially in section and partially in elevation; Fig. 3 is a graph representing the operating conditions in atransformer of my invention; Fig. 4 is a diagrammatic showing of the primary and sec.-

ondary circuits of my transformer and illustrates specifically the manner of connecting the secondary members and their associated loads; and Figs. 5 and 6 are fragmentary views of a portion of the transformer illustrated in Figs. 1 and 2.

One object of my invention is to provide a simple and compact transformer of the moving-coil type by means of which very close regulation of the current supplied by the secondary member may be had. A transformer having this characteristic. is especially desirable for use in connection with motionpicture machines. Many moving- -picture machines now in use are equipped with incandescent lamps which demand close regulation of the current passing through them in order that the highest degree of elliciency may be obtained.

In pursuance of the above object, I propose a moving-coil transformer in which one of the coils, hereafter designated as the secondary coil, for purposes of convenience only, is stationary with respect to a core member, while the primary coil is adapted for movement away from, and toward, the aforesaid secondary coil. Furthermore, I find that if the moving coil be pivoted and restrained in its movement by a particular means, which I shall hereinafter more fully describe, a very close regulation of the current furnished by the secondary coil may be obtained. I preferably employ a resilient restraining means and so adjust the constants thereof that the restraining force exerted thereby shall vary in the same degree as the moment of the pivoted coil, the'moment of the coil in question increasing, of course, as the coil moves farther away from its normal position; that is, the position in WhlCll it is in juxtaposition to, and inductively interlinked with, the secondary coil. So far as I am aware, no such restraining means has heretofore been suggested for use with transformers of this type.

The expression moment of the coil as used throughout this specification and in the attached claims refers to the gravitational component of the forces tending to move the coil multiplied by the horizontal distance between the center of gravity of the coil and the point about which the coil pivots.

As above pointed out, regulating means of the type suggested are of particular benefit in the motion-picture field,.and it should be, noted that it is now common practice for motion-picture houses to employ two projection machines, the machines being used alternately; that is, one machine is employed for projection purposes while the film upon the other machine is being rewound and, if desired, properly focused. A further object of my invention, therefore, is to provide regulating means of such character that both the current required for the projecting machine, as well as that necessary for the purpose of focusing the other machine upon which the film is being rewound, may be furnished from one transformer.

.Ditficulty has been experienced heretofore, however, in accomplishing the above object on account of the instability occasioned when two independent currents of different voltages are drawn from a constant-current transformer. In the structure which I shall hereinafter describe, and the one which I consider most desirable for furnishing power to projection machines, I believe that the derivation of two independent currents would render the operation of the moving coil out of the question unless a particular winding arrangement were employed. In the hereinafter described structure, therefore, I have provided a coil structure which is wound in such manner that, although a smaller auxiliary secondary member is used to supply current at a low voltage to the lamp in that machine, the film in which is being rewound, for focusing purposes, there is no appreciable repulsion occasioned by the additional ampere turns which are set up when the current passes through this secondary coil. I accomplish this result by winding the auxiliary secondary coil in close inductive relation to, and preferably upon the same coil frame as, the primary member. The manner in which this obviates the above-mentioned difliculty will be hereinafter more specifically pointed out.

Referring more particularly to the drawing, and especiall to Figs. 1 and 2, a casing 1 is provided wit lugs 2 and 3 upon which is supported a core member 4 comprising three core-legs 5, 6 and 7 and end yoke members 8 and 9. Embracing the middle leg 6 are memberslO and 11. The member 10 comprises a cylindrical spool 12 and a main primary coil 13, and the member 11 comprises a cylindrical insulating spool 14 and a main secondary coil 15. For purposes of convenience and for promoting the clarity of illustration, 1 have not shown the manner in which the various coils are interconnected. However, reference to Fig. 4 will make clear the manner in which I connect the various coil units, it being noted that I have shown an auxiliary secondary coil 16 connected in series relationship with the main secondary coil 15. In Fig. 2, the auxiliary secondary coil 16 is shown as wound outside of the main primary coil 13. The reason for this specific association of coils will hereinafter be more fully described.

The structure of the insulating cylinder 12 of the coil member 10 projects beyond the latter at both ends of the winding 13 and thereby furnishes a cylindrical seat to which are secured arms 17, 18, 19 and 20. At right angles to the arm members 17 and 18, and formed integrally therewith, is a beam member 21. The arm members 19 and 20 are united and extended downwardly to form a member 22 which is carried upon an axle 23 journaled in upstanding lugs 24. It will be noted that the structure comprising members 17, 18 and 21, together with the connection thereof to the cylindrical insulating member 12, the arms 19 and 20, and the member 22 constitute a pivotally mounted frame or carriage for the member 10 which is adapted to be moved in such manner that the member 10 may assume a position which is in angular relation to its normal position, although it continuously embraces the middle core leg 6. It will be observed that such ivotal movement and the subsequent anguar disposition of the member 10 results in a greatly increased leakage path for the flux which is generated by the ampere turns of the respective windings.

Resilient restraining members 25 and 26 have corresponding ends secured to the ends of the beam 21 and their other ends secured in spring-engaging means 27 and 28, respectively, the last-named means bein pinned to a shaft 29 which is journaled in ugs 30 and 31 projecting from the sides of the casing 1. Likewise, rigidly pinned to the shaft 29 is an adjusting arm 32 which is adapted to move over, and be secured in, anarcuate notched engagable member 33. It will be noted that, by reason of the rigid connection of the members 27 and 28, as well as the adjusting arm 32, to the shaft 29 a movement of the latter downwardly to the right will result in an increase in the tension of the spring members 25 and'26.

In order to eliminate the shock which might otherwise occur when the moving coil 10 is repelled rapidly from the coil 11, a buffer member 34 and associated buffer post 35 are provided.

Referring now more particularly to Fig. 4:, and observlng, in this connection, the structure shown in the lower right-hand corner of Fig. 2, the main primary coil 13, the main secondary coil 15 and the auxiliary secondary coil 16 are shown as connected to two incandescent lamps 36 and 37 through a double-pole, double-throw switch 38 having the switch points a, b, 0, and d and the terminals e and f. In this figure, I have used the lamps 36 and 37 for purposes of illustration and wish it to be understood that they represent, in consistency with other portions'of the description of my invention, projection machines, and further that, as hereinbefore set forth, it is usual for one of the machines to be used for projecting purposes, while the film is being rewound in the other machine, the latter being, at the same time, focused, if desired. While the specified operation and focusing of the machines represented by lamps 36 and 37 constitutes no part of my invention, I have, nevertheless, shown individual switches 39 and 40 by means of which either unit may be cut off from the source of current supply, if so desired. A more specific description of the function of the particular connections shown, when appliedto motion-picture service will be given in the following description of the operation of my transformer.

In the ensuing description, Fig. 3 should be referred to.- In this figure, I have shown, graphically, the manner in which the magnetic repulsive effect between the two coils, the consequent'divergence of the coil 10 from its normal position, and the restraining force of the spring members 25 and 26, are associated.

Inasmuch as I desire to maintain constant current in the secondary circuit which is derived from the main secondary coil ,the consumption apparatus be maintained at-a constant value. In order to accomplish this, I find it necessary to provide a restraining force for the moving member 1'.) which shall increase in exactly the same degree as the moment of the member 10 about its pivotal point of support. Therefore, I select spring members 25- and 26 having such constants that, as they are successively lengthened by the increased force due to the increasing moment arm of the member 10, the moment of the latter is exactly neutralized by the restraining force of the spring members. i Referring to Fig. 3, the distance OX represents the force caused by the repulsion of the member 10 for the member 11. The line OY represents the increase of the gravitational component of the member 10 as it moves farther out of vertical. alinement with its pivotal point. The line XY, reppresents the increasing force exerted by the spring members 25 and 26 as the member 10 moves about its axis, thus elongating said spring. By a suitable choice of springs, the curves OY and XY may be made of exactly opposite equal slopes. If these members have equal but opposite slopes, the algebraic resultant thereof will be a constant force or that represented by the vertical distance between the lines 00 and XX. In this manner, the effect of the gravitational component tending to move the member 10'is eliminated.

If a higher or lower constant secondary current is desired, suitable adjustment of the arm 32 will either increase or decrease the initial spring tension; An adjustment providing an increased initial spring tension is denoted by the spring tension line ZY which is, of course, parallel to the spring tension line XY. The resultant constant force between the forces represented by OY and ZY" equals the vertical distance between the lines 00' and ZZ. The line OY, if sufficiently extended, would become a sine wave, but for the small range of movement here employed, it is substantially a straight line. As the line OY is straight, the increase in the moment of the coil would be exactly proportional to the amount of movement thereof.

As hereinbefore pointed out, another object of my invention is to provide unitary transforming and current-regulating means whereby one load,in this case a projecting machine may be supplied with full voltage,while another load,-in this case a projecting machine in which it is desired to correct the focus.-is being supplied with a different voltage. Moreover, it is desirable that the ampere turns of the various windings supplying such voltages be so adjusted that either machine may be supplied independently with either voltage, that is to say, it may at times be necessary to run only one machine and, (in such circumstances, it is' desirable to have available 3.x source of full voltage for projecting purposes as well as a source of approximately half voltage for use in obtaining the correct focus. In this connection, it may be mentioned that some difficulty has been experienced heretofore in obtaining the proper voltage for the two purposes specified because, when focus correction was being carried out, either resistance had to be inserted in the circuit or it was necessary to arrange a number of taps on the secondary member. In either case, complications arise, and moreover, it is apparently impossible, with either of the last-mentioned methods, to operate an automatic constant current regulating transformer with both of the secondary coils active.

I propose, therefore, to connect the main secondary coil, shown in Fig. 2 at 15, in series with the auxiliary coil 16 and to closely interlink the auxiliary secondary winding and the main primary winding. By so inductively arranging the various windings, am able to neutralize the additional ampere turns which are set up by the auxiliary secondary winding and to prevent, therefore, the added repulsion which would occur if the two secondary windings were placed on the same coil. Were the latter arrangement used, any attempt to derive current from the two secondary members simultaneously would result in an increased repulsion and a consequent derangement of the required constant-current conditions.

Where the arrangement above described is used, however, I find that the increased ampere turns which the auxiliary winding sets up are immediately neutralized-by the opposing ampere turns which its operation occasions in the main primary winding, and, therefore, no increased repulsive effect is set up even though current is derived from both secondary coils simultaneously. This effect is promoted by the very close inductive interlinkage of the auxiliary secondary coil with the main primary coil, since substantially no leakage occurs between the two.

As is illustrated in Fig. 4, a tap connection is brought from between the two secondary members and connected between the two machines. Assuming that the double-pole switch is in the position shown by the dotted lines, a tracing of the circuits discloses the fact that the main secondary winding 15 furnishing full voltage to the lamp 37 while the auxiliary winding 16 is furnishing substantially one-half voltage to the lamp 36. With 128 the conditions shown, the machine with which lamp 37 is used would be employed to project motion pictures upon the screen, whlle the lower-intensity lamp 36 is furnishing just enough light in its associated machine to enable the operator properly to determine the correct focus. It will be observed, therefore, that I have provided, in one structure, requiring the use of a simple transfer switch only, such inductively interlinked windings as will enable two machines to be operated intermittently, there always being the correct conditions present for the use of one machine as a projecting unit, while the focus ofthe other machine is being arranged.

I further contribute to the compactness and the simplicity of a regulating transformer of the character described by placing the aforesaid transfer switch in the position shown in the lower right-hand corner of Fig. 2. All of the operating mechanism, therefore, is enclosed within a fire-proof casing, the switch being operated by a handle 38 which projects outside of the casing.

Referring now to Figs. 5 and 6, which are fragmentary views illustrating modifications of the pivotal mounting 24, I have shown, in the former figure, a pivotal mounting which I consider extremely desirable in transformers of the heretofore-described type. The downwardly extending member 22 is bolted to the axle 23, and the entire structure is mounted upon a resilient member 42. It will be observed that this member 42 is secured to the base of the transformer casing to the left of a vertical axis passing through the normal position of the member 10.. Therefore. as the latter departs from normal, the axle 23 will roll to the left along the resilient member 42, which, by reason of its being secured to the axle, will coil so secure it to the lug 24 and the carriage member 22 that the moment of the moving coil is constantly nullified by the increased tension of the coil spring. I find that, in some cases, this construction simplifies the regulating transformer, to some extent, but the form of retaining spring shown in Fig. 2 is probably more easily adapted for adjustment.

While I-have illustrated but one form of my invention, I desire that no unnecessary limitations shall be placed thereupon and that it be restricted only by the showing of the prior art or by the scope of the appended claims.

I claim as my invention:

1. A core member, coil members inductively associated therewith, one of said coil members being mounted for pivotal movement, and restraining means so opposing the movement of the pivoted coil member that a constant force operates to return said member to normal position.

2. A core member, coil members inductively associated therewith, one of said coil members being mounted for pivotal movement, and restraining means opposing the movement of the pivoted coil member and having an effective returning force which is constantly equal to the gravitational moment of the pivoted coil member when i moves from normal position.

3. A core member, coil members inductivel associated therewith, one of said coil mem ers being mounted for pivotal movement, and resilient restraining means opposing the movement of the pivoted coil mem ber and having a returning force that varies in the same proportion as the gravitational moment of said pivoted coil member when the latter departs from normal position.

4. A core member, primary and secondary coils inductively associated with, and spaced apart on, said core member, one of said coils being pivotally mounted and adapted to be moved away from the other coil by the magnetic repulsion therebetween, and resilient means opposing said movement, the restraining force thereof varying directly as the gravitational moment of said pivotal coil whereby a constant force opposes the divergence of said coils.

5. A core member, primary and secondary coils inductively associated with, and spaced apart on, said core member, one of said coils being pivotally mounted and adapted to be moved away from the other coil by the magnetic repulsion therebetween, resilient means opposing said movement, the restraining force thereof varying directly as the gravitational movement of said pivotal coil whereby a constant force opposes the divergence of said coils, and means for varying the amount of said constant opposing force.

6. A core member, primary and secondary coils inductively associated with, and spaced apart on, said core member, means for pivotally mounting one of said coils, and resilient restraining means associated with said pivotal mounting means and having a returning force that varies in the same proportion as the gravitational moment of said pivotally mounted coil. 1

7 A core member, primary and secondary coils inductivel associatedwith, and spaced apart on, sai core member, means for pivotally mounting one of said coils comprising a frame member carrying said coil and members furnishing journaled supports for said frame, and a coiled resilient member attached to said frame and having a' returning force that varies in the same proportion as the gravitational moment of said pivotally mounted coil.

8. A core member, primary and secondary coils inductively associated with, and spaced apart on, said core member, a flexible member, means for pivotally mounting one of said coils comprising a frame member for carrying said coil mounted on said flexible member, said flexible member being adapted to rotate with said frame member and thereby furnish a substantially frictionless support for the moving coil.

9. A core member, primary and secondary coils inductively associated with, and spaced apart on, said core member, a flexible member, means for pivotally mountlng one of said coils comprising a frame member for carrying said coil mounted on said flexible member, said flxible member being eccentrically secured with respect to a vertical line through the point of support of said moving coil and being thereby adapted to prov1de a substantially frictionless support for said coil.

10. A core member, primary and secondary coils inductively associated with, and spaced apart on, said core member, a flexible member, means for pivotally mounting one of said coils comprising a frame member for carrying said coil mounted on said flexible member, said flexible member being eccentrically secured in the direction of inclination of said movable coil and adapted to imparl't a rolling motion to the support of said 001 11. A core member, primary and secondary coils inductively associated with, and spaced apart on, said core member, one of said coils being pivotally mounted and adapted to be moved away from the other coil b the magnetic repulsion therebetween, resilient means opposing said movement, the restrainin force thereof varying directly as the gravitational moment of said pivotal coil whereby a constant force opposes the divergence of said coils, and an auxiliary secondary winding so associated with t e main primary and secondary coils that no additional repulsive effect is exerted therebetween when said auxiliary secondary windin is loaded.

12. A core member, primary an secondary coils inductively associated with, and spaced apart on, said core member, one of said coils being pivotally mounted and adapted to be moved away from the other coil by the magnetic repulsion therebetween, resilient means opposing said movement, the restraining force thereof varying directly as the gravitational moment of said pivotal coil whereby a constant force opposes the divergence of said coils, and an auxiliary secondary winding so associated with the main rimary and secondarycoils that no apprecia le magnetic is exerted.

14. A core member, main primary and secondary coils having a loose inductive relation to each other and associatedwith said core member, one of said coils being adapted for movement away from the other coil by the magnetic repulsion therebetween, an auxiliary secondary coil having a close inductive relation to said main primary c0il,'g5 whereby no additional repulsive effect between the main primary and secondary coils is exerted, and switching means whereby said secondary windings may independently and simultaneously supply different loads.

15. A core member, main primary and secondary coils having a loose inductive relation to each other and associated with said core member, one of said coils being adapted for movement away from the other coil by the magnetic repulsion therebetween, an auxiliary secondary coil having a close inductive relation to said main primary coil, whereby no additional repulsive effect between the main primary and secondary coils IS exerted, connections whereby said main secondary member may simultaneously supply one load and said auxiliary secondary member another load, and switching means for reversing the connections.

16. In a current-regulating transformer, a core member, a stationary coil member and a pivoted movable coil member having a loose inductive relation to each other, one of said coils consisting entirely of secondary 11 turns and the other coil consisting of both primary and secondary turns, and resilient restraining means for governing the movement of said movable coil,.the restraining force of which varies in the same proportion as the gravitational moment of the movable coil about its support.

17. In a current-regulating transformer,

a core member, a stationary coil and a pivoted movable coil having a loose inductive relation to each other, one of said coils consisting entirely of secondary turns and the other coil consisting of both primary and secondary turns, resilient restraining means for governing the movement of said movable coil, the restraining force of which varies in the same proportion as the gravitational moment of the movable coil about its support, and means for varying the restraining force of said resilient means.

18. In a current-regulating transformer, a core member, a stationary coil member and a pivoted movable coil member having a loose inductive relation to each other, one of said coils consisting entirely of .secondary turns and the other coil consisting of both primary and secondary turns, resilient restraining means for governing the movement of said movable coil, the restraining force of which varies in the same proportion as the gravitational moment of the movable coil about its support, and means for varying the restraining force of said resilient means comprising spring-engaging means, a journaled member to which the engaging means are secured, means secured to said journaled member for moving the same to vary the spring tension, and means for securing the last-named means in a predetermined position.

19. In a current-regulating transformer,

a core member, a stationary coil member and a pivoted movable coil member having a loose inductive relation to each other, one of said coils consisting entirely of secondary turns and the other coil consisting of both primary and secondary turns, resilient restraining means for governing the movement of said movable coil, the restraining force of which varies in the same proportion as the gravitational moment of the movable coil about its support, means for varying the restralning force of said resilient means comprising spring-engaging means, a journaled member to which the engaging means are secured, means secured to said journaled member for moving the same to vary the spring tension, and notched arcuate engagable means for securing the last-named means in a predetermined position.

In testimony whereof, I have hereunto subscribed my name this 11th day of June, 1919.

ALFRED L. ATHERTON. 

